← Barcode generator

Generate a barcode in Node.js

Make product and shipping barcodes: EAN-13, EAN-8, UPC-A, UPC-E, Code 128, Code 39, Code 93, ITF-14 and Codabar, as PNG or SVG. Here is the whole call in Node.js, with the output it produced when we ran it.

Before you start

An API key. Create a free account; it comes with free tokens every month. Put the key in an environment variable so it stays out of your code: export BLOODWEB_KEY=your_key
Node.js 18 or later. Nothing to install: fetch, FormData and Blob are built in. Save the file with the .mjs ending so await works at the top level.

The code

Save it as barcode-generate.mjs and run node barcode-generate.mjs.

// Node.js 18 or later: fetch, FormData and Blob are built in.
import { writeFile } from "node:fs/promises";

const url = new URL("https://bloodweb.net/api/v1/barcode-generate");
url.search = new URLSearchParams({ type: "ean13", data: "590123412345" });

const res = await fetch(url, {
  headers: { Authorization: `Bearer ${process.env.BLOODWEB_KEY}` },
});
if (!res.ok) throw new Error(`${res.status}: ${(await res.json()).error.message}`);
await writeFile("barcode.png", Buffer.from(await res.arrayBuffer()));

What you get

Tested 19 October 2026: this exact code ran against our test copy of the API, which runs the same service code as bloodweb.net, and produced this.

It writes barcode.png: a PNG image, 230 × 106 pixels, 2 KB.

Change the call

Every option the Barcode generator takes. Add or change them the same way as the ones in the code.

data required: What to encode. For EAN and UPC, leave off the check digit and it is added; include it and it is verified.
type: Symbology. One of: code128, code39, code93, ean13, ean8, upca, upce, itf14, codabar.
format: Image format. One of: png, svg.
bar_width: Width of the narrowest bar in pixels. 2 or more for printing.
height: Bar height in pixels.
text: Print the human-readable value under the bars.
color: Bar colour.
background: Background colour, or "transparent".

If it fails

A failed call is not charged. The answer is JSON with an error object; the code above prints its message. The usual ones:

401 missing_key or invalid_key: BLOODWEB_KEY is not set in the shell that runs the code, or the key was revoked.
400 bad_param: a value is wrong or missing. The message names the parameter.
402 insufficient_tokens: the balance does not cover the call. Top up in the dashboard.
429 rate_limited: too many calls at once. Wait the seconds in the Retry-After header and send it again.

Every code and its fix is in the docs.

The Barcode generator page: every option, the limits, and Try it now in your browser.
Getting started: keys, errors and rate limits for all the services.